Aircraft of the autogyro type



March 8, 1938.

A. THAON AIRCRAFT THE AUTOGYRO TYPE Filed June 22, `1955 5 sheets-sheet1 Vxav @W www.. FM

' A TTORNEYS March 8, 1938. A. THAON AIRCRAFT OF THE AUTOGYRO TYPE FiledJune 22 1935 3 Sheets-Sheet 2 ATTORNEYS March 8, 1938.

A. THAON AIRCRAFT oF THE AUTOGYR TYPE Filed June 22, 1935 5`Sheeos-Sheec I5- N VE NTO R nare Taan Patented Mar. 8, 1938 The presentinvention relates to an aircraft of the autogyro type and has for .itsobject to provide an apparatus of this nature adapted for travel uponroads.

This apparatus comprises at le wheel disposed .preferably on the rear,atleast one guide wheel and preferably a pair of guide wheels, and' isadapted to be reduced in size for the purpose of operating as a roadvehicle.

'I'his result is obtained by the use of several particularcharacteristic dispositions by which vthe apparatus can be rapidlychanged over from All of these dispositions are preferably employed incombination but 'a certain number of the same may be used separately,even in an apparatus differing from the one which will be hereinafterdescribed, and without departing from the spirit of the invenast onedriving one use to the other.

A first series of particular dispositions of the apparatus relates tothe landing gear, and this. according to the invention, is so arangedthat the apparatus may occupy two positions, a low and horizontalposition for road travel and a second position which is inclined to thehorizontal in order to facilitate the starting and the land- The wheelsof the landing gear are guide wheels and are preferably arranged in suchWay that their direction may serve both,on the road and in flight,-owing to a suitable'streamlineedevice by which they are transformedinto rudders. They are preferably mounted on an axle'which is combinedwith steering gear and are located at the ends of extensible postssubstantially ver- In a preferred form of construction, the saidextensible posts are so arranged as to permit the rapid change-over fromone position of the apparatus to the other with reference to its landinggear, and to assure for said respective positions either a suspensiontermed road suspension or a suspension termed flight suspension" for theflight and the landing which has `diiierent characteristics from theaforesaid.

According to the invention, the-said posts providing for a pneumaticsuspension by-the displacement of a piston in a cylinder chambercontaining compressed air, said cylinder chamber forms a casing termedprimary casing which is variable according to the length-of the post,and in which/is located asecond casing of constant volume or secondarycasing the passage of the gas from the primary casing into the secondarycasing being allowed when the post is in the road po- UNITED'. STATESPATENT oFFlcE Andre Thann. sz.o1oua, 'France Application June 22, 1935,serial No. zum 4In Luxembourg June 25, 1934 Y s claims. 4(ci. 244-18) csaid cylinder serves 'to form the aforesaid secondary casing, thepassage of the gas from said cylinder and the secondary casing being cutoff when the post'is brought into the flying position by means of avalve device secured to the said piston.

Preferably a cla'ck-valve, controlled by the position of the piston withreference to the cylinder, maintains the post .in its road position, and

- the said valve will open and provide for an admission of air when thelength of the post be' comes reduced below the lower limit which itdetermines.

The control is preferably effected by means of a three-way cock which ismounted within reach of the pilot and is connected to said valve.

. A second series of particular arrangements in the apparatus accordingto the invention relates to the rotor, and the latter, in order toinsure the proper stability of the vehicle on the road and to reduce thegeneral size, is vertically movable. and it can thus take an upper orflying position, or a lower or road position whens it is no longer inrotation.

'Ihis mobility is obtained by deforming the triangular pyramid whichcarries the rotor and a post of which is telescoping for that purpose.

The various controlling operations for the rotor and essentially theraising of this latter, the spreading ofthe blades and the starting, arepreferably obtained by the use of a single control which is so arrangedthat these operations will follow automatically in the 'proper order.v

In conformity with my invention, the control system for the rotor is soarranged that the resistance couples Icorresponding to the controloperations to be effected will increase in value in the same directionas the order of succession of the said operations, and a stop which islo' cated -at the end of .the stroke of each operation will providepositively for-the succeeding operation.

Inthis manner, when the rotor is thrown on,

lthe couple which is brought upon the aggregate been completed that theaforesaid stop will provide for the operation corresponding to the nextresistance couple.

In one embodiment, the raising of the rotor is obtained by the relativerotation of a screw relatively to a, nut, a stop fixed upon said screwbeing adapted to cooperate with said nut the pitch angle of said screwbeing preferably suchk that said latter can be rotated by axial movementof the nut.

'Ihe spreading of the blades and the starting of the rotor arepreferably obtained by means of a driving plate, comprising studsadapted to cooperate on the one hand with stops rigid with a furtherplate connected by links or the like to the blades adapted to be foldedup, and on the other hand with stops rigid with the hub of the rotor,the said lingers making only contact with the last stops providing forthe starting of the rotor after the said further plate has made 'asuilicient rotation for providing for the spreadapparatus relates to thelifting blades and these, v

ing out of the blades.

The change from the flying position to the road position is effected bymeans of a brake which holds the rotor in place; due to the inclinationof the axis to the rear, the blades will be automatically folded up anda brake or the like will then provide for the descent of the wholearrangement. y

A third series of particular dispositions in the in order to reduce thelength of the apparatus on the road and hence to diminish the dangerwhich may be particularly occasioned by side gusts of wind, have alength which is shorter in the idle position than in flight.

For'this purpose, each blade is made in at least two parts of about thesame length, which are in line during the flight and are adapted to bemutuallvdisplaced in such way as to reduce the length of the Wholedevice when the apparatus is transformed into a road vehicle.

In a preferred form of construction, the part of the blade which isfarthest from. the axis of rotation is slidable in the other part; aresilient member constantly urges the slidable part of blade towardssaid axis, and the device is brought into the working position and isheld in this position by the action of the centrifugal force.

A fourth series of particular dispositions in the apparatus relates tothe driving means which are adapted to drive at will from the, motor thepropeller, the propelling means when on the road, or the rotor, whenstarting this latter. The control of the propeller is /preferablysuchthat the latter may be thrown on or oil' the motor at will, and may bestopped in a given position, which. is preferably the horizontalposition, iny order that it will not be too near the ground when on theroad. Y

For this purpose, the propeller coupling com-v prises a device forprogressive driving, a device for gradual braking by friction, a devicefor` positive drive and a device for holding the propeller in a suitableposition. y

In conformity vwith the invention, the propeller is driven by twocooperating members which are bers comprise, on the one hand, taperedbearing parts, and on the other hand, projections or the like by whichthey can be connected together,

u and thus the aforesaid sliding movement serves to drive the propellereither positively or gradually.

Furthermore, a movable braking member may be mounted in contact with asuitable surface in order to brake the propeller, or it may be insertedinto a notch in order to hold the propeller in place.

A iifth series of dispositions relates to the control and this is soarranged that the hand-wheel will also serve for the control of heightin ight, in a known manner, by inclining the axis of the rotor, and forthe control of direction when on the road or in flight.

The apparatus is completed by controls by which the various operationscan be performed from the cockpit.

Other special dispositions, characteristics and advantages of theinvention will be set forth in the following description relating to anembodiment of the invention, with reference to the accompanying drawingswhich are given solely by way of example.

Fig. 1 is an elevational view, with parts broken away, of the apparatusin the flying position.

Figs. 2, 3 and 4 are respectively side, front and plan views of theapparatus after its transformation into a road vehicle.

Fig. 5 is a plan view of the steering gear of the vehicle.

Fig. 6 is a section through a suspension post of the apparatus in which,for the better comprehensionfthe diametrical proportions have beenincreased with reference to the longitudinal proportions.

the principle of the suspension of the apparatus.

Fig. 9 is a plan-e' view with part of a blade broken away.

Fig. 10 is a corresponding perspective view with parts broken away.

Fig. 11 is a sectional view showing a form of the rotor. f

Fig. 12 is a corresponding partial plane View.

Fig. 13 is a sectional view showing the mechanism for driving thepropeller.

Fig. 14 is a partial section on the line XIV-XIV of Fig. 13. n

In the form of construction herein represented, the apparatus comprisesa main body ending at the rear in a stationary vertical fin I and astationary tail plane 2. It is provided at its front end with apropeller 3 and comprises a fore carriage withguide Wheels 4 providedwith a streamline device 5, a' rear driving wheel 6 and a rotor 'I whichis mounted at its upper part, at the top of a pyramid. y

The motor 8 is mounted at the front of the apparatus. It drivesthe'propeller 3 directly by means of a coupling I0 which'will be furtherdescribed, while on the other hand it drives a change-speed box IIthrough the medium of the bevel-gearing I3 and the vertical transmissiondevice I4., The change-speed box II is arranged for at least two speedsand back drive, and it actuates the rear driving wheel 6 or the rotor'I.

'I'he connection with the rear wheel 6 is assured by a Cardan shaft I5and a bevel gear set I6, and the connection with the rotor 'I isassuredby a connection disposed within two telescoping tubes II and I8.

To facilitate the description, I will further set `forth the variouscharacteristic dispositions which are the most important and whichdistinguish the apparatus from the known autogyros, and will alsoindicate their cooperation as well as the means for driving the samefrom the pllots place.

Landing gear and suspension device Fig. 1 shows the apparatus with thelanding gear in the flying position. This apparatus is substantiallyinclined towards the rear. The horizontal visibility is' diminished. Thecenter of gravity is somewhat high. It is thus necessary, in order totransform it into a road vehicle, to

stop the propeller 3 in its horizontal position andl to lower the frontpartof the apparatus in such way that the latter will occupy theposition rhown in Figs. 2 to 3. i

For this purpose, the landing gear consists es-v sentially of a tubularaxle 20 of streamlined shape to each of whose ends is pivoted a respective reaction strut 2l which is also pivoted to the chassis in suchmanner as to absorb the longitudinal stresses and two suspension posts22, substantially vertical,`rigid with said axle, are plvoted to themotor frame and are adapted to sponds to the flying suspension and Fig.8' correthe other hand, a chamber 26, termed secondary f sponds to theroad suspension.

In both cases, the suspension is assured by a piston 23 movable in acylinder 24 containing compressed air, and it is evident that the volumeof compressed air which provides for the suspension will confer to thelatter a greater or less degree of ease and the pressure of the air willremain constant at rest, as it depends only upon the weight of theapparatus. For obtaining with the same organ the two suspensions and thelifting, a certain quantity of liquid 25 is placed in the lower part ofthe cylinder body 24, and on casing, is formed within the piston 23, andit may be connected or not with the primary casing consisting of thesaid cylinder which is situated below it, by 'a valve 21.

In the flyingposltion (Fig. 8), the valve 21 is closed and the secondarycasing 26vis not connected withy the cylinder and thus only the airbetween the layer of liquid and the lower surface of the piston willparticipate in the suspension.

In the road position (Fig. 8'), the secondary casing 2liy is connectedwith' the cylinder and the quantity of compressed air which it containswill thus participate in the suspension.

For the travel on the road (Fig. 8'), the rela- I tive. position of theparts is such that the distance from. the lower end of the piston v23 tothe end of the cylinder 24 is substantially equal to the stroke of thesuspension.

' For the landing, the volume of air participating in the suspension isincreasedv by the volume of the cylinder 24 corresponding to the'lifting stroke, and diminished, on the one hand by the volume of theliquid 25 and on the other hand by the volume of the secondary casing26.

This will afford, in either case, volumes of air corresponding toappropriate suspensions, and it.

will be noted that it is sumcient to admit air into-the cylinder inorder to change over from the road position to the flying position.

Figs. 6 and 7 show a construction of asuspension post of the typedescribed, Fig. 6 representing the flying position and Fig. '7 the roadposition. v

The device consists of a cylinder body 24 which is secured to the axle22 (Fig. 5) .and in which is movable a tubular piston 23 linkedto themotor frame. Leakless conditions are obtained by the use of a pressedleather piece 28 and a certain quantity of oil is placed at the bottomof this body. The secondary casing is formed within the said cylinderforming the primary casing by a tube 29 which is pierced at its lowerend with slots 30 adapted to provide for the communication of saidcasings for the road suspension.

Any passage of air from. said primary casing .into said secondary casingis cut oi during the flying by a packing device consisting of twopressed leather pieces 3| and 32 or the like, which are mounted on rod33 secured to the tubular piston 23. The tube 29 is subjected totheaction of a spring 35 bearing against the rod 33 and urging itdownwardly in such way as to break all connection between the twocasings, this movement being limited by an inner shoulder 36 formed onthe tube 29.

The rod 33 carries at its'upper part a valve 31 whose head 38 extendsoutwardly. This head 38 is arranged so as to open the valve 31 against aspring 40 when the rod is lowered below a certain level after the' slots3|l have been uncovered.

Two conduits, one of which, 42, yis connected with the valve 31, and theother, 4'3, is connected with the closing member 32, lead to a three-waycock 44 which is located infront of the pilot and is adapted to connectthe said conduits with the atmosphere (by the conduit 45) or with'acompressed air tank y(46 in Fig. 1), by the conduit 41.

The whole arrangement is completed by a hydraulic shock-absorber of aknown type, which is distinct from ,the suspension itself, and serves toprevent the jumping of the apparatus. This closing rod 33 is nowin itsupper 'position and -thus there is noother connection between thetwo,casings but through the two leather members 3I-32 which only allow thecompressed air to circulate in one direction. Thus the air con tained inthe secondary casing 26 does not par,- ticipate in the suspension, andthe connection between this casing and the supply, which is constantlymaintained, only serves `to compensate for the leakage.

In order to change over to the road position, the piping 4". isconnected with the egghaust. The Valve 31 is lifted by the air'pressjr'rie 'and the ventire casing is emptied; the weight of theapparatus causes the piston 23 to descend. This latter descends to apoint below the position shown in Fig. 7 and thus the two casings willcommunicate through the slots 30 and the valve 31 will be held open,owing to the contact between its head and the inner surface cf the tube29.

-The cock 44 islthen turned in order to` connect the tube 42 withv theintake of compressed air.

This air fills theY two casings and it raises the piston 23 to theposition shown in Fig. 7, in which position the valve 31 is released andcuts off the supply of compressed air.

The chassis is now maintained at a constant height above the ground, asthe leakage is compensated by an intake of air due to the opening of thevalve 31 under the eil'ectoof the tube 29, as soon as the piston 23tends to descend.

On the other hand, the whole of the air contained in the chamber is nowutilized for the suspension.

Steering The axle 20, which is tubular and streamlined, carries at itsends the journals of the wheels 4.

Within this axle 2li is contained the steering gear, which consists of agear-wheel 52 cooperating with a rack 53 connected by ball-and-socketjoints to bars 54 pivoted to rods 55 controlling the direction of thewheels 4. The rotation of the vehicle wheel 52 is controlled by thehandwheel 68 with which the vehicle wheel is connected by Cardan jointsor the like connected by two sliding tubes 56-51 provided with iiutings.

As shown in a greater scale on Fig. 11, the hub 5l of the rotor ismounted in ball bearings in an inclinable support 62 which is pivoted tothe axle-pin 63 at the top of the triangular pyramid formed by thedevice consisting of the telescoping tubes Ii-IS, which are pivotallymounted on the change-speed box and of two stays 65 mounted on xedpivots 66 (Fig. 1).

The sails of the rotor consist of two blades 12,

each of whose arms is' mounted on the hub by means of a horizontal pivot14 (Fig. 1 1) and of a vertical pivot 15 (Fig. 12). and of a blade 16whose arm is mounxad only on a horizontalpivot.

"Ihe two blades 12 may be folded about the said vertical pivots so thatthe whole device may take the position shown in Figs. 2, 3 and 4. A disc11, actuated by the shaft 18, either directly or indirectly through aplanetary speed-reduction device, as will be further disclosed, carriesstuds 19 cooperating on the one hand with stops 88 mounted on a plate 8|and on the other hand with stops 82 mounted on the h ub 6|.

Upon the plate 8| are pivoted, by ball-andsocket joints, two rods 84which may be elastic and are pivoted by other ball-and-socket joints tothe blades 12, said stops being so arranged thatl the studs 19 will comeagainst them before making contact withthe stops 82 of the hub 6| Thecontrol of the lifting, the unfolding and the starting of the rotor isobtained from the motor, and it is combined in suchmanner that theresistance couples corresponding to these three operations, and,possibly to other operations intervening, shall proceed in an order ofincrease which is as marked as possible, and a stop device used for theend of the movement will correspond to the completion of an operationcoinciding with the commencement of the next operation correspending toa couple whose value is immediately above the former. v I

For this purpose, the power is transmitted from the change-speed box tothe shaft 83 which is provided with one or more screwthreads adapted forreversible screwing into a nut' mounted on the tube 85. The direction ofthe thread is such that the rotation of the shaft 83, by an unscrewingeffect, will raise the tube 85 together Vwith the rotor until it abutsagainst the head 84 of the shaft 83. The pitch angle is such that thescrew can be rotated by axial movement of the nut. Obviously, theresistance couple corresponding to the rise of the nut is less than theresistance couple of the other operations.

The tube 85 will thus actuate the shaft 18, by means of the Cardan joint86. This shaft 18 drives as above indicated the disc 11 whose studs 19will rst come against the two stops 80 on the triangular plate 8|. Asshown in Fig. 12, a rotation of the plate 8| in the direction of thearrow will open out the blades 12, before the rotor device is set inrotation, due to the eifects of gravity and of inertia of the blades I2which are less than those of the rotor as a whole.

It is only when the blades 'l2 are opened out, that the studs 19 willcome against the stops 82 of the rotor hub and will thus cause therotation of this latter.

When changing over from flying to road conditions, the operations aredistinct from one another, and these are preferably eifected as follows.A brake hand 98, surrounding the cylinclrlcal part of the rotor hub 6|,provides for the stopping of this latter preferably with the blade 19 inthe rearward direction. In these conditions, by inclining the rotorshaft entirely to the rear, the action of gravity will be sufficient tofold up the blades 12. As concerns the descent of the rotor, use is madeof a lowering brake consisting C'. a lever 9| which is provided with ashoe 92 and a stud 93 and is mounted on the lower end of the movabletube I8. The weight of the lever or preferably the effect of a springwill serve, at the end of the rising movement of the rotor, to hold thetubes |1-I8 in place by the insertion of the stud 93 into a notch in thetube I1. For the de- 'A scent of the rotor, an upward movement of the Inthe form of construction represented in Figs. 9 and 10, each rotor bladeconsists of a hollow half-blade 98 pivoted to the arm 13, and of ahalfblade 99 which is slidable in the first-mentioned half-blade, thefriction being reduced to a minimum by the use of rollers IDU-IDI. Astretcher or elastic cord device |02 connects the outer end of thehalf-made ss to the inner end of the haifblade 98. It is evident thatthe action of centrifugal force will have a preponderating effect on thestarting of the rotor, and that the halfblade 99-will be drivenoutwardly, and thus it will serve for the lifting ofthe apparatus.Inversely,

when the rotor is braked, the blades will be automatically telescopedunder the action of the stretcher |02 when the said rotor falls below adetermined speed.

An important feature of the construction of the blades consists in theabutment when in the operating position, which should be such that noplay will be allowed when in flight,` a s this would cause dangerousvibrations.

In order to provide for an abutment without the least play, it isobtained by tting, without jamming two dihedral angles one within theother. Said dihedral angles are advantageously separated into two parts,in order to increase the 11tting length and their surfaces are disposedbetween the two entering edges |03 of the blades on the one hand and thetwo trailing edges |04 onvedge of the movable half-blade, havingat each10, of the bars, a slight distortion will be produced, which iscompatible with the iiexibilty A of the blades.

Propeller coupling device 15 The propeller coupling device |0 isintended to allow thev pilot to obtain at will either a progressivedriving of the propeller by friction, a positive driving, aprogressive'braking by friction, or a stopping in a given position,which is usually 20 the horizontal position, in order that the apparatusmay be lowered without inconvenience.

In the form of construction shown in Figs. 13 and 14 in which it issupposed that the propeller 3 is perpendicular to the plane of theiigure, the 25 propeller coupling device comprises a sleeve ||0 whichcarries the propeller and is secured, by -rmeans 'of a tapered bearingpart, to the end of the crankshaft ||2 in the place of the usualpropeller hub. The said sleeve Y| I is provided with 30 flutings bywhich it constantly drives the movable coupling device ||3 whose slidingis effected by a fork H4. The propeller hub I|5 is rotatable by means ofbronze rings ||6 on the sleeve |||l. It is secured to the propeller andto 35 the driving disc ||8. The sliding device ||3 and the disc ||3comprise tapered bearing por-v tions H9 and iiutings |20 which are soarranged that the sliding device will move the disc and the A propellereither by the friction of the tapered 40, parts ||9 when it is driven tothe front, or by the utings |20 which come into engagement when it isdriven to the rear. The disc IIB also comprises two shoulders, one ofwhich, |2I, is continuous and the other, |22, is interrupted by 45 thenotches |23. A movable stud |24 is sc arranged that it will either brakethe propeller by friction upon the Acontinuous shoulder |2I, or willstop the same in a given position when it is inserted into a notch |23.This stopping device 50 may be made to depend upon a safety device,

.provided with a spring or the like, which prevents an abnormal stresson the end of a blade from breaking the supportI .|25 of themovablestud.

Rods |30 and |3| lead to the cockpit and Apermit to displace the slidingdevice `or to control the movable stud |24.

Cont/rolling devices On the other hand, the hand-wheel 60 servesl forthe steering, as above disclosed, the steering being effected when onthe ground by means of the steering wheels 4, and when in ight, due to 0the streamline arrangement 5 of these wheels,

which now serve Vas rudders. The hand-wheel 60 is mounted at the end ofa tube |32 pivoted by means of a Cardanjoint 68 to the tube 51 and 75connected on the other hand with the inclinable support 62 ofthe rotorby a strut |33 pivoted to the frame a'bar |34, a countershaft |35 andtelescoping bars |36 and |31.

This arrangement permits tocontrol the inclination of the axis of therotor and hence the rise and descent, by moving' the hand-wheel to thefront or rear.

The telescoping bars |31 and |36 are fastened together by a. pin or thelike when flying and on the other hand the strut |33 is fastened withreference to'the frame during the travelling on road.

of any suitable type, by which all errors of operation are avoided.

While I have described what I at present conl sider preferredembodiments ofV my invention, it will be obvious to those skilled in theart that various changes and modifications may be made without departingfrom my invention and I therefore aim in the appended claims to coverall such changes and modifications as fall within the true spirit andscope of my invention.

What I claim is: l. In an autogyro apparatus,A a. body, a rotor, atleast one post attached on the body for sup- Y porting said rotor, saidpost including two members in slidable engagement, one of said membersbeing pivoted to said body and the other to said rotor, control meansfor sliding said members one with reference to the other to reduce thesize of the apparatus.

2. An autogyro apparatus as claimed in claim 1 wherein one of saidmembers is screw threaded "and the other is tubular and includes a nutadapted to cooperate with said screw threaded member, means for drivingone of said shafts, a stop fixed upon said screw threaded shaft andadapted to limit the lengthening motion of said post.

3. An autogyro apparatus as claimed in claim 1 wherein one of saidmembers is provided with a screw thread and the other is tubular andincludes a nut adapted to cooperate with said screw threaded member, thepitch angle being such that the screw can be rotated by axial movementof the nut, means for driving one oi said members, a. stop xed uponsaidthreadedmember and adapted to limit the relative sliding motion in 'thedirection corresponding to the lengthening of the post, a tubesurrounding said screw threaded member, means connected with said tubefor braking the telescoping motion of the post corresponding to thereduction of `its length. v

4. In an autogyro apparatus, a body, a motor, a rotor including anactuating shaft, at least one post adapted to support said rotor, saidpost including a screw threaded-shaft, a nut adapted to cooperate with.said shaft, the pitch angle 'being such that the screw can be rotated byaxial movement oi' the nut, a tubular member connected to said nut, astop carried by said screw threaded shaft and adapted to limit thelengthening motion of said post, driving means, one end of said tubularmember and screw threaded shaft being connectedto said driving means andthe other to said actuating shaft, the resisting torque corresponding tothe starting of the rotor being greater than the torque corresponding tothe lengthening of said post.

.5. An autogyro apparatus as claimed in claim 4, including two furtherposts adapted to support the rotor.

6, In an autogyro apparatus, a body, an en- The apparatus'is completedby safety devices gine, a rotor, at least one post attached to saidbody-for supporting said rotor, said post including at leasttwo membersin sliding engagement,

one of said members being attached to said body and the other to saidrotor, a screw and nut contrivance operatively connected to said membersand adapted to cause a sliding motion of one of said members withreference to the other, a stop adapted to limit said sliding motion,transmission means between said engine and said contrivance foroperating said latter, a connection between said contrivance and saidrotor and adapted to start the rotor, the resisting torque correspondingto the sliding of said members in the direction corresponding to anupward movement of the rotor being smaller than the resistance torquecorresponding to the starting of the rotor.

7. An autogyro apparatus as claimed in claim 6, in which the pitch angleof said screw and nut contrivance is such that the screw can be rotatedby axial movement of the nut.

8. In an autogyro apparatus, a body, an engine, at least one post, arotor pivotally supported by said post, said post being swinginglycarried by said body to swing the rotor substantially in the verticaland longitudinal median plane ofthe apparatus, a screw and nutcontrivance connected respectively to said body and to said rotor toswing said post and reduce the high of the apparatus, transmission meansbetween said engine and said contrivance and adapted to operate saidlatter and to thus displace the rotor in the upward direction, aconnection between said rotor and said contrivance adapted to start saidrotor, a stop adapted to limit the displacement of the rotor in theupward direction, the resisting torque corresponding to saiddisplacement of the rotor being smaller than the resisting torquecorresponding to the starting of the rotor.

9. In an autogyro apparatus, a body, an engine, at least one post, arotor pivotally supported by said post, said post being swinginglycarried by said body to swing the rotor substantially in the verticaland longitudinal median plane of the apparatus, a screw and nutcontrivance connected respectively to said body and to said rotor toswing said post and reduce the high of the apparatus, the pitch angle ofsaid contrivance being such that the screw can be rotated by axialmovement of the nut, transmission means between said engine and saidcontrivance adapted to operate said latter and to thus displace therotor in the upward direction, a connection between said rotor and saidcontrivance adapted to start said rotor, a stop adapted to limit thedisplacement of the rotor in the upward direction, the resisting torquecorresponding to said displacement of the rotor being smaller than theresisting torque corresponding to the starting of the rotor.

ANDR THAON.'

